Paul G wrote:Secondly, I seem to recall, possibly in the voiceovers or perhaps I read it, but that Bryant himself had a liver defect, making him unable to drink himself, hence the comment in the movie "Drink one for me, Pal"

Exactly:

In his 1980 Blader Runner Script, Hampton Fancher wrote:DECKARD (V.O.) Bryant's got a liver problem. A couple years back he handed me a bottle and said have a drink for another man. I been drinking for him ever since.